In a press release today, the index committee at Dow Jones, which publishes Barron's, cited the low stock prices of the three companies being removed as well as a "desire to diversify the sector and industry group representation of the index."

Diversification is a worthwhile goal, but the index committee missed an opportunity to add a giant company with huge annual sales whose business is much more representative of the American economy than any of three companies added.

Most of Berkshire's sales are domestic, and it's exposed to a wide swath of the economy with ownership of the Burlington Northern and a slew of industrial and financial businesses. Berkshire's class B shares, now trading at around $113, could have been added to the Dow. An addition of Berkshire to the Dow industrial would have been a crowning achievement for CEO Warren Buffett, who took control of the company in 1965 when its market value was around $30 million.

The index committee also passed on adding Google and Apple to the Dow. That probably would have required a tweak to the current Dow structure, which weights each of the 30 members by their stock prices. With Google at $887 and Apple at $500, either would have overwhelmed the index. What the index committee could have done – but evidently chose not to do -- was put in either company based on a fractional share. Apple could have been added at a quarter of its stock price, or roughly $125 currently.

Other large and worthy companies that were passed up were Oracle and Ford Motor. Ford's revival would have made it a nice addition to the Dow, a replacement for General Motors, which was dumped in 2009 on its way to bankruptcy. Ford has many domestic factories, employs thousands of workers in the U.S. and makes most of its profits domestically. One problem with Ford, which has a market value of $70 billion, is its low stock price of $17.

Alcoa and Bank of America, which are being booted from the Dow, were recently trading at $8.09 and $14.69, respectively.

The addition of Goldman and Visa will give those two companies disproportionate influence in the Dow thanks to their high stock prices. Goldman, at $163, and Visa, at $183, will have weightings of 7.7% and 6.9%, respectively, according to Birinyi Associates. Visa and Goldman will be No. 2 and No. 3 in importance, just behind IBM, which has a share price of $187. Goldman and Visa will have outsized influence relative to their market values. For perspective, Goldman, with a market value of $75 billion, will shockingly have about five times the weight of Microsoft, which has triple Goldman's market value.

Such is the quirk – and arguably the problem – of the Dow industrials. With the index changes, which will take effect on Sept. 23, five stocks will account for a third of index: IBM, Visa, Goldman, Chevron and 3M. Four large companies with sizable market values, Pfizer, Cisco Systems, General Electric and Intel, have a combined weighting of less than 5% -- under that of Goldman – thanks to the Dow's price weighting.

Goldman is an odd choice because it's not a traditional financial company that focuses on lending money. It makes most of its profits from trading and its outlook hinges on things like regulatory actions like the Volcker rule. Visa essentially is a toll taker on global financial transactions.